Surgical instrument with dual mode articulation drive

ABSTRACT

A surgical instrument includes a shaft assembly and an articulation control assembly. The shaft assembly includes an articulation section. The distal end of the shaft assembly is configured to receive an end effector. The articulation section is configured to deflect the end effector from the longitudinal axis. The articulation control assembly includes a first articulation control member, a second articulation control member, and a transmission assembly. The transmission assembly includes a high ratio drive and a low ratio drive. The high ratio drive is configured to drive the articulation section to deflect the end effector at a high rate of articulation in response to actuation of the first articulation control member. The low ratio drive is configured to drive the articulation section to deflect the end effector at a low rate of articulation in response to actuation of the second articulation control member.

PRIORITY

This application is a continuation of U.S. patent application Ser. No.17/314,684, entitled “Surgical Instrument with Dual Mode ArticulationDrive,” filed May 7, 2021, published as U.S. Pub. No. 2021/0346049,which is a continuation of U.S. patent application Ser. No. 16/429,127,entitled “Surgical Instrument with Dual Mode Articulation Drive,” filedJun. 3, 2019, and issued as U.S. Pat. No. 11,364,047 on Jun. 21, 2022,which is a continuation of U.S. patent application Ser. No. 15/088,357entitled “Surgical Instrument with Dual Mode Articulation Drive,” filedApr. 1, 2016, issued as U.S. Pat. No. 10,492,819 on Dec. 3, 2019.

BACKGROUND

A variety of surgical instruments include an end effector having a bladeelement that vibrates at ultrasonic frequencies to cut and/or sealtissue (e.g., by denaturing proteins in tissue cells). These instrumentsinclude piezoelectric elements that convert electrical power intoultrasonic vibrations, which are communicated along an acousticwaveguide to the blade element. The precision of cutting and coagulationmay be controlled by the surgeon's technique and adjusting the powerlevel, blade edge, tissue traction and blade pressure.

Examples of ultrasonic surgical instruments include the HARMONIC ACE®Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONICFOCUS® Ultrasonic Shears, and the HARMONIC SYNERGY® Ultrasonic Blades,all by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. Further examplesof such devices and related concepts are disclosed in U.S. Pat. No.5,322,055, entitled “Clamp Coagulator/Cutting System for UltrasonicSurgical Instruments,” issued Jun. 21, 1994, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,873,873, entitled“Ultrasonic Clamp Coagulator Apparatus Having Improved Clamp Mechanism,”issued Feb. 23, 1999, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 5,980,510, entitled “Ultrasonic ClampCoagulator Apparatus Having Improved Clamp Arm Pivot Mount,” filed Oct.10, 1997, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,325,811, entitled “Blades with Functional BalanceAsymmetries for use with Ultrasonic Surgical Instruments,” issued Dec.4, 2001, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,773,444, entitled “Blades with Functional BalanceAsymmetries for Use with Ultrasonic Surgical Instruments,” issued Aug.10, 2004, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool with UltrasoundCauterizing and Cutting Instrument,” issued Aug. 31, 2004, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.8,461,744, entitled “Rotating Transducer Mount for Ultrasonic SurgicalInstruments,” issued Jun. 11, 2013, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 8,591,536, entitled“Ultrasonic Surgical Instrument Blades,” issued Nov. 26, 2013, thedisclosure of which is incorporated by reference herein; and U.S. Pat.No. 8,623,027, entitled “Ergonomic Surgical Instruments,” issued Jan. 7,2014, the disclosure of which is incorporated by reference herein.

Still further examples of ultrasonic surgical instruments are disclosedin U.S. Pub. No. 2006/0079874, entitled “Tissue Pad for Use with anUltrasonic Surgical Instrument,” published Apr. 13, 2006, now abandoned,the disclosure of which is incorporated by reference herein; U.S. Pub.No. 2007/0191713, entitled “Ultrasonic Device for Cutting andCoagulating,” published Aug. 16, 2007, now abandoned, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2007/0282333,entitled “Ultrasonic Waveguide and Blade,” published Dec. 6, 2007, nowabandoned, the disclosure of which is incorporated by reference herein;U.S. Pub. No. 2008/0200940, entitled “Ultrasonic Device for Cutting andCoagulating,” published Aug. 21, 2008, now abandoned, the disclosure ofwhich is incorporated by reference herein; and U.S. Pub. No.2010/0069940, entitled “Ultrasonic Device for Fingertip Control,”published Mar. 18, 2010, now U.S. Pat. No. 9,023,071, issued May 5,2015, the disclosure of which is incorporated by reference herein.

Some ultrasonic surgical instruments may include a cordless transducersuch as that disclosed in U.S. Pub. No. 2012/0112687, entitled “RechargeSystem for Medical Devices,” published May 10, 2012, now U.S. Pat. No.9,381,058, issued Jul. 5, 2016, the disclosure of which is incorporatedby reference herein; U.S. Pub. No. 2012/0116265, entitled “SurgicalInstrument with Charging Devices,” published May 10, 2012, nowabandoned, the disclosure of which is incorporated by reference herein;and/or U.S. Pat. App. No. 61/410,603, filed Nov. 5, 2010, entitled“Energy-Based Surgical Instruments,” the disclosure of which isincorporated by reference herein.

Additionally, some ultrasonic surgical instruments may include anarticulating shaft section and/or a bendable ultrasonic waveguide.Examples of such ultrasonic surgical instruments are disclosed in U.S.Pat. No. 5,897,523, entitled “Articulating Ultrasonic SurgicalInstrument,” issued Apr. 27, 1999, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,989,264, entitled“Ultrasonic Polyp Snare,” issued Nov. 23, 1999, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 6,063,098, entitled“Articulable Ultrasonic Surgical Apparatus,” issued May 16, 2000, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,090,120, entitled “Articulating Ultrasonic Surgical Instrument,”issued Jul. 18, 2000, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 6,454,782, entitled “Actuation Mechanismfor Surgical Instruments,” issued Sep. 24, 2002, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 6,589,200, entitled“Articulating Ultrasonic Surgical Shears,” issued Jul. 8, 2003, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,752,815, entitled “Method and Waveguides for Changing the Direction ofLongitudinal Vibrations,” issued Jun. 22, 2004, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 7,135,030, entitled“Articulating Ultrasonic Surgical Shears,” issued Nov. 14, 2006; U.S.Pat. No. 7,621,930, entitled “Ultrasound Medical Instrument Having aMedical Ultrasonic Blade,” issued Nov. 24, 2009, the disclosure of whichis incorporated by reference herein; U.S. Pub. No. 2014/0005701,published Jan. 2, 2014, now U.S. Pat. No. 9,393,037, issued on Jul. 16,2016, entitled “Surgical Instruments with Articulating Shafts,” thedisclosure of which is incorporated by reference herein; U.S. Pub. No.2014/0005703, entitled “Surgical Instruments with Articulating Shafts,”published Jan. 2, 2014, now U.S. Pat. No. 9,408,622, issued on Aug. 9,2016, the disclosure of which is incorporated by reference herein; U.S.Pub. No. 2014/0114334, entitled “Flexible Harmonic Waveguides/Blades forSurgical Instruments,” published Apr. 24, 2014, now U.S. Pat. No.9,095,367, issued on Aug. 4, 2015, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2015/0080924, entitled“Articulation Features for Ultrasonic Surgical Instrument,” publishedMar. 19, 2015, now U.S. Pat. No. 10,172,636, issued on Jan. 8, 2019, thedisclosure of which is incorporated by reference herein; and U.S. patentapplication Ser. No. 14/258,179, entitled “Ultrasonic Surgical Devicewith Articulating End Effector,” filed Apr. 22, 2014, the disclosure ofwhich is incorporated by reference herein.

While several surgical instruments and systems have been made and used,it is believed that no one prior to the inventors has made or used theinvention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a side elevational view of a first exemplary ultrasonicsurgical instrument;

FIG. 2 depicts a perspective view of an articulation section of a shaftassembly and an end effector of the surgical instrument of FIG. 1 ;

FIG. 3 depicts an exploded perspective view of the articulation sectionof the shaft assembly of FIG. 2 ;

FIG. 4 depicts a cross-sectional side view of the shaft assembly and endeffector of FIG. 2 ;

FIG. 5 depicts a top plan view of the shaft assembly and end effector ofFIG. 2 ;

FIG. 6A depicts a cross-sectional top view of the shaft assembly and endeffector of FIG. 2 in a straight configuration;

FIG. 6B depicts a cross-sectional top view of the shaft assembly and endeffector of FIG. 2 in an articulated configuration;

FIG. 7 depicts a partially exploded perspective view of the shaftassembly and end effector of FIG. 2 ;

FIG. 8 depicts a perspective view of a distal collar and a drive cableof the shaft assembly of FIG. 2 ;

FIG. 9 depicts a partially exploded perspective view of an shaft controlassembly of the instrument of FIG. 1 ;

FIG. 10A depicts a side elevational view of the end effector and thedistal portion of the shaft assembly of FIG. 2 , with a clamp arm of theend effector in a closed position, and with an outer sheath shown incross-section to reveal components within the outer sheath;

FIG. 10B depicts a side elevational view of the end effector and thedistal portion of the shaft assembly of FIG. 2 , with the clamp armmoved to a fully open position, and with an outer sheath shown incross-section to reveal components within the outer sheath;

FIG. 11 depicts a side elevational view of a second exemplary ultrasonicsurgical instrument having a shaft control assembly;

FIG. 12 depicts a partially exploded side elevation view of theultrasonic surgical instrument of FIG. 11 , with a disposable assemblyseparated from a reusable assembly;

FIG. 13 depicts a partially exploded front perspective view of thedisposable assembly of FIG. 12 , which includes a shaft control assemblyhaving a dual mode articulation control assembly;

FIG. 14 depicts a front perspective view of the dual mode articulationcontrol assembly of FIG. 13 ;

FIG. 15 depicts a partially exploded front perspective view of the dualmode articulation control assembly of FIG. 13 ;

FIG. 16 depicts an front perspective view of an articulation drum of thedual mode articulation control assembly of FIG. 13 ;

FIG. 17 depicts a rear perspective view of the articulation drum of FIG.16 ;

FIG. 18 depicts an exploded front perspective view of a lead screw ofthe dual mode articulation control assembly of FIG. 13 ;

FIG. 19 depicts an exploded rear perspective view of another lead screwof the dual mode articulation control assembly of FIG. 13 ;

FIG. 20 depicts an upper front perspective view of a dual sensitivitydrive of the dual mode articulation control assembly of FIG. 13 ;

FIG. 21 depicts a lower rear perspective view of the dual sensitivitydrive of FIG. 20 ;

FIG. 22 depicts an upper perspective view of a low sensitivityarticulation control knob of the dual sensitivity drive of FIG. 20 ;

FIG. 23 depicts a lower perspective view of the low sensitivityarticulation control knob of FIG. 22 ;

FIG. 24 depicts a rear perspective view of a drive coupling of the dualsensitivity drive of FIG. 20 ;

FIG. 25 depicts a front perspective view of the drive coupling of FIG.24 ;

FIG. 26 depicts a rear perspective view of a drive drum of the dualsensitivity drive of FIG. 20 ;

FIG. 27 depicts a front perspective view of the drive drum of FIG. 26 ;

FIG. 28 depicts an upper perspective view of a high sensitivityarticulation control knob of the dual sensitivity drive of FIG. 20 ;

FIG. 29 depicts a lower perspective view of the high sensitivityarticulation control knob of FIG. 28 ;

FIG. 30 depicts an enlarged side elevational view of the disposableassembly of FIG. 12 , having various components removed for clarity;

FIG. 31 depicts an enlarged side elevational view of the disposableassembly of FIG. 12 , having various components removed for clarity,including an articulation drum removed for illustrating a straightconfiguration for a shaft assembly;

FIG. 32 depicts an enlarged side elevational view of the disposableassembly of FIG. 12 , having various components removed for clarity,showing the low sensitivity articulation control knob having beenmanipulated to actuate the articulation section of the shaft assembly;and

FIG. 33 depicts an enlarged side elevational view of the disposableassembly of FIG. 12 , having various components removed for clarity,showing the high sensitivity articulation control knob having beenmanipulated to actuate the articulation section of the shaft assembly.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal,” “distal,” “upper,” and“lower” are defined herein relative to a human or robotic operator ofthe surgical instrument. The term “proximal” refers the position of anelement closer to the human or robotic operator of the surgicalinstrument and further away from the surgical end effector of thesurgical instrument. The term “distal” refers to the position of anelement closer to the surgical end effector of the surgical instrumentand further away from the human or robotic operator of the surgicalinstrument. The terms “proximal,” “distal,” “upper,” and “lower” arethus relative terms and not intended to unnecessarily limit theinvention described herein.

Furthermore, for additional clarity of the disclosure, the terms “high”and “low” are defined herein with respect to transmission ratios oftransmission input to transmission output. For example, a “high”transmission ratio results in a predetermined input yielding arelatively “high” transmission output, but with less sensitivity toinput. In contrast, a “low” transmission ratio results in thepredetermined input yielding a relatively “low” transmission output, butwith greater sensitivity to input. It will be appreciated that suchconcepts similarly apply to “high” and “low” gearing ratios inmechanical transmission assemblies. To this end, the terms “high” and“low” are relative terms and not intended to unnecessarily limit theinvention described herein.

I. Exemplary Ultrasonic Surgical Instrument

FIG. 1 shows an exemplary ultrasonic surgical instrument (10). At leastpart of instrument (10) may be constructed and operable in accordancewith at least some of the teachings of any of the various patents,patent application publications, and patent applications that are citedherein. As described therein and as will be described in greater detailbelow, instrument (10) is operable to cut tissue and seal or weld tissue(e.g., a blood vessel, etc.) substantially simultaneously.

Instrument (10) of the present example comprises a handle assembly (20),a shaft assembly (30), and an end effector (40). Handle assembly (20)comprises a body (22) including a pistol grip (24) and a pair of buttons(26). Handle assembly (20) also includes a trigger (28) that ispivotable toward and away from pistol grip (24). It should beunderstood, however, that various other suitable configurations may beused, including but not limited to a scissor grip configuration. Endeffector (40) includes an ultrasonic blade (160) and a pivoting clamparm (44). Clamp arm (44) is coupled with trigger (28) such that clamparm (44) is pivotable toward ultrasonic blade (160) in response topivoting of trigger (28) toward pistol grip (24); and such that clamparm (44) is pivotable away from ultrasonic blade (160) in response topivoting of trigger (28) away from pistol grip (24). Various suitableways in which clamp arm (44) may be coupled with trigger (28) will beapparent to those of ordinary skill in the art in view of the teachingsherein. In some versions, one or more resilient members are used to biasclamp arm (44) and/or trigger (28) to the open position shown in FIG. 1.

An ultrasonic transducer assembly (12) extends proximally from body (22)of handle assembly (20). Transducer assembly (12) is coupled with agenerator (16) via a cable (14), such that transducer assembly (12)receives electrical power from generator (16). Piezoelectric elements intransducer assembly (12) convert that electrical power into ultrasonicvibrations. Generator (16) may include a power source and control modulethat is configured to provide a power profile to transducer assembly(12) that is particularly suited for the generation of ultrasonicvibrations through transducer assembly (12). By way of example only,generator (16) may comprise a GEN04 or GEN11 sold by EthiconEndo-Surgery, Inc. of Cincinnati, Ohio. In addition or in thealternative, generator (16) may be constructed in accordance with atleast some of the teachings of U.S. Pub. No. 2011/0087212, entitled“Surgical Generator for Ultrasonic and Electrosurgical Devices,”published Apr. 14, 2011, now U.S. Pat. No. 8,986,302, issued on Mar. 24,2015, the disclosure of which is incorporated by reference herein. Itshould also be understood that at least some of the functionality ofgenerator (16) may be integrated into handle assembly (20), and thathandle assembly (20) may even include a battery or other on-board powersource such that cable (14) is omitted. Still other suitable forms thatgenerator (16) may take, as well as various features and operabilitiesthat generator (16) may provide, will be apparent to those of ordinaryskill in the art in view of the teachings herein.

A. Exemplary End Effector and Acoustic Drivetrain

As best seen in FIGS. 2-4 , end effector (40) of the present examplecomprises clamp arm (44) and ultrasonic blade (160). Clamp arm (44)includes a clamp pad (46) that is secured to the underside of clamp arm(44), facing blade (160). Clamp pad (46) may comprisepolytetrafluoroethylene (PTFE) and/or any other suitable material(s).Clamp arm (44) is pivotally secured to a distally projecting tongue (43)of an upper distal shaft element (172), which is fixedly secured withina distal portion of a distal outer sheath (33). Clamp arm (44) isoperable to selectively pivot toward and away from blade (160) toselectively clamp tissue between clamp arm (44) and blade (160). A pairof arms (156) extend transversely from clamp arm (44) and are pivotallysecured to a lower distal shaft element (170), which is slidablydisposed within the distal portion of distal outer sheath (33).

As best seen in FIGS. 7-8 , a cable (174) is secured to lower distalshaft element (170). Cable (174) is operable to translate longitudinallyrelative to an articulation section (130) of shaft assembly (30) toselectively pivot clamp arm (44) toward and away from blade (160). Inparticular, cable (174) is coupled with trigger (28) such that cable(174) translates proximally in response to pivoting of trigger (28)toward pistol grip (24), and such that clamp arm (44) thereby pivotstoward blade (160) in response to pivoting of trigger (28) toward pistolgrip (24). In addition, cable (174) translates distally in response topivoting of trigger (28) away from pistol grip (24), such that clamp arm(44) pivots away from blade (160) in response to pivoting of trigger(28) away from pistol grip (24).

Lower distal shaft element (170) comprises a pair of distal flanges(171, 173) extending from a semi-circular base (168). Flanges (171, 173)each comprise a respective opening (175, 177). Clamp arm (44) isrotatably coupled to lower distal shaft element (170) via a pair ofinwardly extending integral pins (41, 45). Pins (41, 45) extend inwardlyfrom arms (156) of clamp arm (44) and are rotatably disposed withinrespective openings (175, 177) of lower distal shaft element (170). Asshown in FIGS. 10A-10B, longitudinal translation of cable (174) causeslongitudinal translation of lower distal shaft element (170) between aproximal position (FIG. 10A) and a distal position (FIG. 10B).Longitudinal translation of lower distal shaft element (170) causesrotation of clamp arm (44) between a closed position (FIG. 10A) and anopen position (FIG. 10B).

Blade (160) of the present example is operable to vibrate at ultrasonicfrequencies in order to effectively cut through and seal tissue,particularly when the tissue is being compressed between clamp pad (46)and blade (160). Blade (160) is positioned at the distal end of anacoustic drivetrain, which includes transducer assembly (12) and anacoustic waveguide (180). Acoustic waveguide (180) comprises a flexibleportion (166), which is associated with articulation section (130).Transducer assembly (12) is operable to convert electrical power intoultrasonic vibrations, which are then transmitted along waveguide (180)to blade (160) in accordance with known configurations and techniques.By way of example only, this portion of the acoustic drivetrain may beconfigured in accordance with various teachings of various referencesthat are cited herein.

As best seen in FIG. 3 , flexible portion (166) of waveguide (180)includes a distal flange (136), a proximal flange (138), and a narrowedsection (164) located between flanges (136, 138). In the presentexample, flanges (136, 138) are located at positions corresponding tonodes associated with resonant ultrasonic vibrations communicatedthrough flexible portion (166) of waveguide (180) (i.e., at locationswhere the vibrational amplitude is minimal). Narrowed section (164) isconfigured to allow flexible portion (166) of waveguide (180) to flexwithout significantly affecting the ability of flexible portion (166) ofwaveguide (180) to transmit ultrasonic vibrations. By way of exampleonly, narrowed section (164) may be configured in accordance with one ormore teachings of U.S. Pub. No. 2014/0005701, now U.S. Pat. No.9,393,037, issued on Jul. 29, 2016, and/or U.S. Pub. No. 2014/0114334,now U.S. Pat. No. 9,095,367, issued on Aug. 4, 2015, the disclosures ofwhich are incorporated by reference herein. Various suitable ways inwhich waveguide (180) may be mechanically and acoustically coupled withtransducer assembly (12) will be apparent to those of ordinary skill inthe art in view of the teachings herein.

Those of ordinary skill in the art will understand that, as a matter ofphysics, the distal end of blade (24) is located at a positioncorresponding to an anti-node associated with resonant ultrasonicvibrations communicated through waveguide (28) (i.e., at an acousticanti-node). When transducer assembly (12) is energized, the distal endof blade (160) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency fo of, for example, 55.5 kHz. Whentissue is compressed between blade (160) and clamp pad (46), theultrasonic oscillation of blade (160) may simultaneously sever thetissue and denature the proteins in adjacent tissue cells, therebyproviding a coagulative effect with relatively little thermal spread.

In some versions, end effector (40) is operable to apply radiofrequency(RF) electrosurgical energy to tissue in addition to applying ultrasonicenergy to tissue. By way of example only, end effector (40) may beconfigured and operable in accordance with at least some of theteachings of U.S. Pub. No. 2015/0141981, entitled “Ultrasonic SurgicalInstrument with Electrosurgical Feature,” published May 21, 2015, nowU.S. Pat. No. 9,949,785, issued on Apr. 24, 2018, the disclosure ofwhich is incorporated by reference herein; and/or U.S. Pat. No.8,663,220, entitled “Ultrasonic Electrosurgical Instruments,” issuedMar. 4, 2014, the disclosure of which is incorporated by referenceherein. Other suitable configurations for an acoustic transmissionassembly and transducer assembly (12) will be apparent to one ofordinary skill in the art in view of the teachings herein. Similarly,other suitable configurations for end effector (40) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

B. Exemplary Shaft Assembly and Articulation Section

Shaft assembly (30) of the present example extends distally from handleassembly (20). As shown in FIGS. 2-7 , shaft assembly (30) includesdistal outer sheath (33) and a proximal outer sheath (32) that encloseclamp arm (44) drive features and the above-described acoustictransmission features. Shaft assembly (30) further includes anarticulation section (130), which is located at a distal portion ofshaft assembly (30), with end effector (40) being located distal toarticulation section (130). As shown in FIG. 1 , a rotation controlassembly (102) has rotation control member in the form of rotationcontrol knob (31), which is secured to a proximal portion of proximalouter sheath (32). Knob (31) is rotatable relative to body (22), suchthat shaft assembly (30) is rotatable about the longitudinal axisdefined by outer sheath (32), relative to handle assembly (20). Suchrotation may provide rotation of end effector (40), articulation section(130), and shaft assembly (30) unitarily. Of course, rotatable featuresmay simply be omitted if desired.

Articulation section (130) is operable to selectively position endeffector (40) at various lateral deflection angles relative to alongitudinal axis defined by outer sheath (32). Articulation section(130) may take a variety of forms. By way of example only, articulationsection (130) may be configured in accordance with one or more teachingsof U.S. Pub. No. 2012/0078247, now U.S. Pat. No. 9,402,682, issued onAug. 2, 2016, the disclosure of which is incorporated by referenceherein. As another merely illustrative example, articulation section(130) may be configured in accordance with one or more teachings of U.S.Pub. No. 2014/0005701, now U.S. Pat. No. 9,393,037, issued on Jul. 29,2016, and/or U.S. Pub. No. 2014/0114334, now U.S. Pat. No. 9,095,367,issued on Aug. 4, 2015, the disclosures of which are incorporated byreference herein. Various other suitable forms that articulation section(130) may take will be apparent to those of ordinary skill in the art inview of the teachings herein.

As best seen in FIGS. 2-6B articulation section (130) of this examplecomprises a set of three retention collars (133) and a pair of ribbedbody portions (132, 134), with a pair of articulation bands (140, 142)extending along respective channels (135, 137) defined between interiorsurfaces of retention collars (133) and exterior surfaces of ribbed bodyportions (132, 134). Ribbed body portions (132, 134) are longitudinallypositioned between flanges (136, 138) of flexible portion (166) ofwaveguide (180). Ribbed body portions (132, 134) are configured to flexwith flexible portion (166) of waveguide (180) when articulation section(130) bends to achieve an articulated state.

FIG. 3 shows ribbed body portions (132, 134) in greater detail. Ribbedbody portion (132) comprises a set of three ribs (150) that areconfigured to promote lateral flexing of ribbed body portion (132).Ribbed body portion (132) also defines a channel (135) that isconfigured to receive articulation band (140) while allowingarticulation band (140) to slide relative to ribbed body portion (132).Similarly, ribbed body portion (134) comprises a set of three ribs (152)that are configured to promote lateral flexing of ribbed body portion(134). Of course, any other suitable number of ribs (150, 152) may beprovided. Ribbed body portion (134) also defines a channel (137) that isconfigured to receive articulation band (142) while allowingarticulation band (142) to slide relative to ribbed body portion (137).

As best seen in FIG. 5 , ribbed body portions (132, 134) are laterallyinterposed between articulation bands (140, 142) and flexible portion(166) of waveguide (180). Ribbed body portions (132, 134) mate with eachother such that they together define an internal passage sized toaccommodate flexible portion (166) of waveguide (180) without contactingwaveguide (180). In addition, when ribbed body portions (132, 134) arecoupled together, a pair of complementary distal notches (131A, 131B)formed in ribbed body portions (132, 134) align to receive a pair ofinwardly projecting resilient tabs (38) of distal outer sheath (33).This engagement between tabs (38) and notches (131A, 131B)longitudinally secures ribbed body portions (132, 134) relative todistal outer sheath (33). Similarly, when ribbed body portions (132,134) are coupled together, a pair of complementary proximal notches(139A, 139B) formed in ribbed body portions (132, 134) align to receivea pair of inwardly projecting resilient tabs (37) of proximal outersheath (32). This engagement between tabs (37) and notches (139A, 139B)longitudinally secures ribbed body portions (132, 134) relative toproximal outer sheath (32). Of course, any other suitable kinds offeatures may be used to couple ribbed body portions (132, 134) withproximal outer sheath (32) and/or distal outer sheath (33).

The distal ends of articulation bands (140, 142) are unitarily securedto upper distal shaft element (172). When articulation bands (140, 142)translate longitudinally in an opposing fashion, this will causearticulation section (130) to bend, thereby laterally deflecting endeffector (40) away from the longitudinal axis of shaft assembly (30)from a straight configuration as shown in FIG. 6A to an articulatedconfiguration as shown in FIG. 6B. In particular, end effector (40) willbe articulated toward the articulation band (140, 142) that is beingpulled proximally. During such articulation, the other articulation band(140, 142) may be pulled distally by upper distal shaft element (172).Alternatively, the other articulation band (140, 142) may be drivendistally by an articulation control. Ribbed body portions (132, 134) andnarrowed section (164) are all sufficiently flexible to accommodate theabove-described articulation of end effector (40). Furthermore, flexibleacoustic waveguide (166) is configured to effectively communicateultrasonic vibrations from waveguide (180) to blade (160) even whenarticulation section (130) is in an articulated state as shown in FIG.6B.

As best seen in FIG. 3 , each flange (136, 138) of waveguide (180)includes a respective pair of opposing flats (192, 196). Flats (192,196) are oriented along vertical planes that are parallel to a verticalplane extending through narrowed section (164) of flexible portion(166). Flats (192, 196) are configured to provide clearance forarticulation bands (140, 142). In particular, flats (196) of proximalflange (138) accommodate articulation bands (140, 142) between proximalflange (138) and the inner diameter of proximal outer sheath (32): whileflats (192) of distal flange (136) accommodate articulation bands (140,142) between distal flange (136) and the inner diameter of distal outersheath (33). Of course, flats (192, 196) could be substituted with avariety of features, including but not limited to slots, channels, etc.,with any suitable kind of profile (e.g., square, flat, round, etc.). Itshould also be understood that waveguide (180) may include flats formedin accordance with at least some of the teachings of U.S. Pub. No.2013/0289592, entitled “Ultrasonic Device for Cutting and Coagulating,”filed Apr. 23, 2013, published on Oct. 31, 2013, now U.S. Pat. No.10,238,416, issued on Mar. 26, 2019, the disclosure of which isincorporated by reference herein.

In the present example, outer rings (133) are located at longitudinalpositions corresponding to ribs (150, 152), such that three rings (133)are provided for three ribs (150, 152). Articulation band (140) islaterally interposed within channel (135) between rings (133) and ribbedbody portion (132); while articulation band (142) is laterallyinterposed within channel (137) between rings (133) and ribbed bodyportion (134). Rings (133) are configured to keep articulation bands(140, 142) in a parallel relationship, particularly when articulationsection (130) is in a bent configuration (e.g., similar to theconfiguration shown in FIG. 6B). In other words, when articulation band(140) is on the inner diameter of a curved configuration presented by abent articulation section (130), rings (133) may retain articulationband (140) such that articulation band (140) follows a curved path thatcomplements the curved path followed by articulation band (142). Itshould be understood that channels (135, 137) are sized to accommodaterespective articulation bands (140, 142) in such a way that articulationbands (140, 142) may still freely slide through articulation section(130), even with rings (133) being secured to ribbed body portions (150,152). It should also be understood that rings (133) may be secured toribbed body portions (132, 134) in various ways, including but notlimited to interference fitting, adhesives, welding, etc.

When articulation bands (140, 142) are translated longitudinally in anopposing fashion, a moment is created and applied to a distal end ofdistal outer sheath (33) via upper distal shaft element (172). Thiscauses articulation section (130) and narrowed section (164) of flexibleportion (166) of waveguide (180) to articulate, without transferringaxial forces in articulation bands (140, 142) to waveguide (180).

As best seen in FIG. 9 , an articulation control assembly (100) issecured to a proximal portion of outer sheath (32). Articulation controlassembly (100) comprises a housing (110) and a rotatable articulationcontrol knob (120). As shown and described herein, articulation controlassembly (100) and rotation control assembly (102) collectively define ashaft control assembly (98). Housing (110) comprises a pair ofperpendicularly intersecting cylindrical portions (112, 114). Knob (120)is rotatably disposed within a first hollow cylindrical portion (112) ofhousing (110) such that knob (120) is operable to rotate withincylindrical portion (112) of housing (110). Shaft assembly (30) isslidably and rotatably disposed within a second hollow cylindricalportion (114). Shaft assembly (30) comprises a pair of translatablemembers (161, 162), both of which extend slidably and longitudinallythrough the proximal portion of outer sheath (32). Translatable members(161, 162) are longitudinally translatable within second cylindricalportion (114) between a distal position and a proximal position.Translatable members (161, 162) are mechanically coupled with respectivearticulation bands (140, 142) such that longitudinal translation oftranslatable member (161) causes longitudinal translation ofarticulation band (140), and such that longitudinal translation oftranslatable member (162) causes longitudinal translation ofarticulation band (142).

Knob (120) comprises a pair of pins (122, 124) extending downwardly froma bottom surface of knob (120). Pins (122, 124) extend into secondcylindrical portion (114) of housing (110) and are rotatably andslidably disposed within a respective pair of channels (163A, 163B)formed in top surfaces of translatable members (161, 162). Channels(163A, 163B) are positioned on opposite sides of an axis of rotation ofknob (120), such that rotation of knob (120) about that axis causesopposing longitudinal translation of translatable members (161, 162).For instance, rotation of knob (120) in a first direction causes distallongitudinal translation of translatable member (161) and articulationband (140), and proximal longitudinal translation of translatable member(162) and articulation band (142); and rotation of knob (120) in asecond direction causes proximal longitudinal translation oftranslatable member (161) and articulation band (140), and distallongitudinal translation of translatable member (162) and articulationband (142). Thus, it should be understood that rotation of rotation knob(120) causes articulation of articulation section (130).

Housing (110) of articulation control assembly (100) comprises a pair ofset screws (111, 113) extending inwardly from an interior surface offirst cylindrical portion (112). With knob (120) rotatably disposedwithin first cylindrical portion (112) of housing (110), set screws(111, 113) are slidably disposed within a pair of arcuate channels (121,123) formed in knob (120). Thus, it should be understood that rotationof knob (120) will be limited by movement of set screws (111, 113)within channels (121, 123). Set screws (111, 113) also retain knob (120)in housing (110), preventing knob (120) from traveling vertically withinfirst cylindrical portion (112) of housing (110).

An interior surface of first cylindrical portion (112) of housing (110)comprises a first angular array of teeth (116) and a second angulararray of teeth (118) formed in an interior surface of first cylindricalportion (112). Rotation knob (120) comprises a pair of outwardlyextending engagement members (126, 128) that are configured to engageteeth (116, 118) of first cylindrical portion (112) in a detentrelationship to thereby selectively lock knob (120) in a particularrotational position. The engagement of engagement members (126, 128)with teeth (116, 118) may be overcome by a user applying sufficientrotational force to knob (120); but absent such force, the engagementwill suffice to maintain the straight or articulated configuration ofarticulation section (130). It should therefore be understood that theability to selectively lock knob (120) in a particular rotationalposition lock will enable an operator to selectively lock articulationsection (130) in a particular deflected position relative to thelongitudinal axis defined by outer sheath (32).

In some versions of instrument (10), articulation section (130) of shaftassembly (30) is operable to achieve articulation angles up to betweenapproximately 15° and approximately 30°, both relative to thelongitudinal axis of shaft assembly (30) when shaft assembly (30) is ina straight (non-articulated) configuration. Alternatively, articulationsection (130) may be operable to achieve any other suitable articulationangles.

II. Exemplary Shaft Control Assembly with Dual Mode Articulation ControlAssembly

It may be desirable to provide a dual mode articulation control assemblythat is operable to drive articulation of articulation section (130)with various input sensitivities. In some instances, an operator maywish to rapidly provide a relative large degree of articulation ofarticulation section (130) with relatively little input sensitivity(e.g., less accuracy and/or less precision for positioning end effector(40)). In some other instances, an operator may wish to provide a fineradjustment of articulation with relatively greater input sensitivity(e.g., more accuracy and/or more precision for positioning end effector(40)). The following description relates to an exemplary ultrasonicsurgical instrument (210) having a dual mode articulation controlassembly (218) that includes at least two articulation control members(222, 223) with differing high and low transmission ratios for improvedarticulation control of shaft assembly (216). Aside from the differencesdescribed below, instrument (210) of this example is configured andoperable just like instrument (10) described above.

As shown in FIGS. 11-12 , instrument (210) of the present examplefurther includes a shaft assembly (212), a handle assembly (214), endeffector (40), and acoustic waveguide (80) extending therealong. Asdiscussed above, acoustic waveguide (80) is operatively connected togenerator (16) and shaft assembly (212), which includes articulationsection (130) for positioning end effector (40) during a surgicalprocedure. To this end, surgical instrument (210) includes a shaftcontrol assembly (216) that is configured to rotate shaft assembly (212)about the longitudinal axis and articulate articulation section (130).Shaft control assembly (216) more particularly includes an articulationcontrol assembly (218) that is operatively connected to the articulationsection (130); and a rotation control assembly (220) that is operativelyconnected to shaft assembly (212). Articulation control assembly (218)includes a high articulation control member (222) and a low articulationcontrol member (223). Rotation control assembly includes a rotationcontrol member (224). Articulation control assembly (218) furtherincludes a transmission assembly (226) with a high ratio drive (227)(see FIG. 14 ) and a low ratio drive (228) (see FIG. 14 ) configured torespectively transmit selective manipulation of high and lowarticulation control members (222, 223) to shaft assembly (212) forflexing articulation section (130) with two distinct inputsensitivities.

A distal portion of shaft control assembly (216) extends along aproximal portion of shaft assembly (212). A proximal portion of shaftcontrol assembly (216) is contained within a disposable assembly (230)of surgical instrument (210). Disposable assembly (230) is configured toremovably connect with handle assembly (214) to form surgical instrument(210). By way of example only, handle assembly (214) may be configuredand operable in accordance with at least some of the teachings of U.S.patent application Ser. No. 14/868,574, entitled “Ultrasonic SurgicalInstrument with Removable Handle Assembly,” filed on Sep. 25, 2015, nowpublished as U.S. Pat. Pub. No. 2016/0015419, published on Jan. 21,2016, issued as U.S. Pat. No. 10,349,967 on Jul. 16, 2019, thedisclosure of which is hereby incorporated by reference in its entirety.By way of further example only, assemblies (214, 230) may coupletogether (and decouple from each other) in accordance with at least someof the teachings of U.S. patent application Ser. No. 14/868,574,entitled “Ultrasonic Surgical Instrument with Removable HandleAssembly,” filed on Sep. 25, 2015, now published as U.S. Pat. Pub. No.2016/0015419, published on Jan. 21, 2016, issue as U.S. Pat. No.10,349,967 on Jul. 16, 2019, the disclosure of which is herebyincorporated by reference in its entirety. Alternatively, assemblies(214, 230) may couple together (and decouple from each other) in anyother suitable fashion. In some other versions, instrument (210) isconstructed without separable assemblies (214, 230). For instance,instrument (210) may instead be constructed just like instrument (10),but with articulation control assembly (218) replacing articulationcontrol assembly (100).

As shown in FIG. 13 , a lateral side portion of disposable assembly(230) is removed to more clearly illustrate the proximal portion ofshaft control assembly (216). In one example, rotation and high and lowarticulation control members (224, 222, 223) are respectively in theform of a selectively rotatable rotation control knob (224) andselectively rotatable high and low articulation control knobs (222,223). Rotation control knob (220) extends along the longitudinal axis ofshaft assembly (212) and is configured to rotate about the longitudinalaxis. In contrast, high articulation control knob (222) extends along ahigh transverse axis and is configured to rotate about the hightransverse axis; while low articulation control knob (223) extends alonga low transverse axis and is configured to rotate about the lowtransverse axis. Thus, rotation control knob (224) rotatesperpendicularly relative to high and low articulation control knobs(222, 223). Rotation and low articulation control knobs (223, 224) areeach also positioned proximate to trigger (28) of handle assembly (214)such that the operator can access and manipulate trigger (28), rotationcontrol knob (224), and low articulation control knob (223) with thesame single hand that grasps pistol grip (24).

In the present example, low articulation control knob (223) is receivedwithin a knob slot (231) (see FIG. 30 ), transversely positioned betweenrotation control knob (224) and trigger (28). High articulation controlknob (222) extends from an upper surface of housing (22). While theabove description positions exemplary shaft control assembly (216) atleast partially within handle assembly (214) with the positions of therotation and low articulation control knobs (224, 223) proximate totrigger (28), it will be appreciated that one or more portions of shaftcontrol assembly (216) may be alternatively positioned for operativeconnection with shaft assembly (212). Thus, the invention is notintended to be unnecessarily limited to the specific orientation andplacement of the shaft control assembly (216) as described herein.

FIGS. 14-15 illustrate shaft control assembly (216) and a pair oftranslatable members (232, 233), which extend to respective articulationbands (140, 142) for directing articulation along shaft assembly (216)as discussed above with respect to shaft assembly (30) (see FIG. 3 ).Translatable members (232, 233) differ from translatable members (161,162) by at least having a pair of longitudinal slots (234, 236) thatextend laterally through translatable members (232, 233) to respectivelyreceive pins (not shown). Pins (not shown) extend through rotationcontrol knob (224) such that pins (not shown) secure rotation controlknob (224) to translatable members (232, 233). Thus, as the operatorselectively rotates rotation control knob (224) about the longitudinalaxis of shaft assembly (212), rotation control knob (224) causesrotation of translatable members (232, 233) and the other portions ofshaft assembly (212) about the longitudinal axis as discussed above withrespect to surgical instrument (10) (see FIG. 1 ). Additional componentsof rotation control assembly (220) will be discussed below in furtherdetail.

Transmission assembly (226) is configured to transmit selectivemovement, such as rotational input by the operator via high and lowarticulation control knobs (222, 223), to shaft assembly (212) forarticulating articulation section (130) (see FIG. 11 ). Transmissionassembly (226) includes a drive drum (244), a high ratio drive (227)connected to high articulation control member, and a low ratio drive(228) connected to low articulation control member (223). High and lowratio drives (227, 228) are each connected to drive drum (244) fortransmitting manipulation therethrough as discussed below in greaterdetail. A distal end of drive drum (244) rigidly connects to a proximalend of an articulation drum (252) such that each surrounds and isconfigured to rotate about the longitudinal axis for directingarticulation of articulation section (130) (see FIG. 11 ).

To this end, with respect to FIGS. 15-17 , articulation control assembly(216) further includes a frame (253), a proximal lead screw (254), and adistal lead screw (256) received within articulation drum (252) forconverting rotation of articulation drum (252) to linear movement oflead screws (254, 256) to thereby articulate articulation section (130)(see FIG. 11 ). In the present example, frame (253) had a pair ofgenerally parallel and offset longitudinal tracks (258) received withinrespective recesses (260). Tracks (258) are configured to preventrotation of proximal and distal lead screws (254, 256) while allowingfor translation of lead screws (254, 256) along the longitudinal axis.Rotation of articulation drum (216) is configured to cause translationof lead screws (254, 256). More particularly, proximal lead screw (254)threadably engages proximal inner threads (262), while distal lead screw(256) threadably engages distal inner threads (264). Proximal and distalinner threads (262, 264) have opposing pitches relative to each othersuch that rotation of drum (252) results in translation of proximal anddistal lead screws (254, 256) in opposing directions.

In addition, lead screws (254, 256) are each respectively connected totranslatable members (232, 233) via respective tensioners (266) as shownin FIGS. 18-19 . Each tensioner (266) has a key (268) engaged with therespective translatable member (232, 233) to direct movement oftranslatable members (232, 233) distally or proximally along thelongitudinal axis via high and low articulation control knobs (222,223). However, each tensioner (266) also rotatably receives itsrespective lead screw (254, 256) within an annular channel (270) suchthat each lead screw (254, 256) and articulation drum (252) arecollectively configured to be rotated via rotation control knob (224)(see FIG. 11 ) when rotating shaft assembly (212) without affectingarticulation. By way of example, each tensioner (266) is defined by aC-shaped component (272), which includes key (268), and an annularcomponent (274). Further details regarding articulation drum (252), leadscrews (254, 256), and other various similarities with articulationcontrol assembly (218) are described in U.S. patent application Ser. No.14/688,663 entitled “Ultrasonic Surgical Instrument with Opposing ThreadDrive for End Effector Articulation,” filed on Apr. 16, 2015, nowpublished as U.S. Pat. Pub. No. 2016/0302820, published on Oct. 20,2016, issued as U.S. Pat. No. 10,342,567 on Jul. 9, 2019, the disclosureof which is incorporated by reference herein in its entirety.

On one hand, either of high and low articulation control knobs (222,223) may be selectively rotated by the operator to articulatearticulation section (130) (see FIG. 11 ) through transmission assembly(226) as shown in FIGS. 14-19 . On the other hand, transmission assembly(226) is configured to inhibit inadvertent articulation of articulationcontrol assembly (218) by operatively locking transmission assembly(226) when high and low articulation control knobs (222, 223) are notbeing rotated. In other words, rotation of either one of high and lowarticulation control knobs (222, 223) effectively unlocks articulationcontrol assembly (218), otherwise transmission assembly (226)effectively locks articulation of articulation section (130) (see FIG.11 ). By way of example, self-locking of transmission assembly (226)occurs because forces imposed on lead screws (254, 256) via shaftassembly (212) (e.g., when end effector (40) encounters transverselyoriented loads imposed by anatomical structures or other surgicalinstruments, etc.) are incapable of providing sufficient mechanicaladvantage to rotate articulation drum (252). However, rotatingarticulation drum (252) via high and low articulation control knobs(222, 223) unlocks movement with sufficient mechanical advantage overlead screws (254, 256) to translate lead screws (254, 256) andarticulate articulation section (130) (see FIG. 11 ). In the presentexample, articulation control knobs (222, 223) each have respectivenotches (275 a, 275 b) positioned angularly thereabout. Notches (275 a,275 b) are configured to provide improved grip to the operator whilemanipulating the high and low articulation control knobs (222, 223).

FIGS. 20-21 show high and low ratio drives (227, 228) connected to highand low articulation control members (222, 223) for dual modearticulation as briefly discussed above. In the example shown in FIGS.20-23 , high ratio drive (227) includes a high face gear (276) having aplurality of teeth (278) extending downwardly from high articulationcontrol knob (222). Teeth (278) are arranged in a starburst pattern.High face gear (276) is unitarily formed with high articulation controlknob (222) in the present example. Alternatively, high face gear (276)may be rigidly connected to high articulation control knob (222) byanother structure, such as a shaft. High face gear (276) is thusconfigured to be rotatably driven about the high transverse axissimultaneously with high articulation control knob (222).

As also shown in FIGS. 20-21 and FIGS. 24-27 , high face gear (276) isoperatively connected drive drum (244) via a spur gear (280) and a drivecoupling (282). Spur gear (280) is an integral feature of drive drum(244), located at the proximal end of drive drum (244). Spur gear (280)has a plurality of teeth (284) projecting radially outwardly about thelongitudinal axis of drive drum (244). Drive coupling (282) has aproximal gear (286), a distal gear (288), and a coupling shaft (290)extending rigidly therebetween. Proximal gear (286) is in the form of aspur gear; while distal gear (288) is in the form of a bevel gear. Gears(286, 288) rotate together unitarily with shaft (290). In particular,gears (286, 288) and shaft (290) are configured to rotate about an axisthat is generally parallel to the longitudinal axis defined by shaftassembly (212) (see FIG. 11 ). High face gear (276) meshes with distalgear (288), while proximal gear (286) meshes with spur gear (280). Thus,coupling (282) is configured to transmit rotation of high articulationcontrol knob (222) to drum (244), such that drum (244) will rotate inresponse to rotation of knob (222).

In order to provide a compact form factor to high ratio drive (227),distal gear (289) is nested within a hollow (292) of high articulationcontrol knob (222). While high ratio drive (227) includes high face gear(276), spur gear (280), and drive coupling (282) for driving drive drum(244) as discussed herein, it will be appreciated that alternativemechanisms configured to direct movement of drive drum (244) and/orarticulation drum (252). By way of example, high ratio drive (227) mayalternatively include other mechanical and/or electrical assemblies forflexing shaft assembly (212). The invention is thus not intended to beunnecessarily limited to high ratio drive (227) of the present example.

As shown in FIGS. 20-21 and 26-29 , low ratio drive (228) of the presentexample includes a low drive shaft (294) extending rigidly upwardly fromlow articulation control member (223) to a low drive gear (296) forengagement with a low face gear (298). Low drive gear (296) is in theform of a bevel gear and is rigidly connected to low drive shaft (294)such that low articulation control member (223), low drive shaft (294),and low drive gear (296) are configured to be simultaneously rotatedbout the low transverse axis. Low face gear (298) is an integral featureof drive drum (244), located distal to spur gear (280). Low face gear(298) includes a plurality of teeth (300) projecting proximally in astarburst arrangement about the longitudinal axis of drive drum (244).Low face gear (298) meshes with low drive gear (296). While low facegear (298) and distal gear (288) are located in close proximity witheach other in this example, it should be understood that gears (288,298) do not actually mesh with each other in this example.

Since low face gear (298) meshes with low drive gear (296), rotation oflow drive gear (296) via low articulation control member (223) and lowdrive shaft (294) will provide rotation of drive drum (244) about thelongitudinal axis of drive drum (244). It should be understood that thebevel gear configuration of low drive gear (296) will provide thisrotation despite drive drum (244) and low drive shaft (294) beingoriented along respective axes that are angled 90 degrees from eachother. While low ratio drive (228) includes low drive shaft (294), lowdrive gear (296), and low face gear (298) for driving drive drum (244)as discussed herein, it will be appreciated that alternative mechanismsconfigured to direct movement of drive drum (244) and/or articulationdrum (252). By way of example, low ratio drive (228) may alternativelyinclude other mechanical and/or electrical assemblies for flexing shaftassembly (212). The invention is thus not intended to be unnecessarilylimited to exemplary low ratio drive (228) of the present example.

As noted above, drive drum (244), spur gear (280), and low face gear(298) are unitarily formed together in the present example and are thusconfigured to rotate collectively and simultaneously for transmittingrotation therethrough for driving articulation drum (252).Alternatively, one or more of drive drum (244), spur gear (280), and lowface gear (298) may be formed separately and then affixed together via asecurement, such as a separate fastener, integral clip, adhesive, orweld, etc. By way of further example, drive drum (244) includes a distalflange (304) and an annular body (304) proximally extending therefrom.Distal flange (302) defines a plurality of angularly spaced key slots(306) that are configured to engage a respective plurality of annularlyspaced key tabs (308) (see FIG. 17 ) defined by a proximal end ofarticulation drum (252) (see FIG. 17 ) for driving rotation ofarticulation drum (252) (see FIG. 17 ). Furthermore, annular body (304)of drive drum (244) and spur gear (280) have approximately equivalentouter diameters. In contrast, low face gear (298) surrounds annular body(304) about the longitudinal axis such that annular body (304) has anouter diameter approximately equivalent to an inner diameter of low facegear (298).

FIGS. 30-31 show articulation control assembly (218) in a straightconfiguration, but with articulation drum (252) removed to reveal leadscrews (254, 256). As shown in FIG. 32 , the operator manipulates higharticulation control knob (222) clockwise (when viewed from above) forrightward articulation of articulation section (130) (see FIG. 11 ). Inturn, high articulation control knob (222) drives coupling shaft (290)clockwise (when viewed from the view of the operator during use).Coupling shaft (290) engages spur gear (280) to direct drive drum (244)counterclockwise, which similarly directs articulation drum (252)counterclockwise. As articulation drum (252) rotates counterclockwise,proximal and distal inner threads (262, 264) translate proximal anddistal lead screws (254, 256) longitudinally away from each other towarda desirable right configuration. High articulation control knob (222)thus operatively connects to drive drum (244) with high ratio drive(227) such that a predetermined amount of clockwise rotation of higharticulation control knob (222) results in a relatively large degree ofarticulation of articulation section (130) (see FIG. 11 ). The operatormay thus quickly and efficiently selectively move end effector (40) (seeFIG. 11 ) toward tissue, but with the less sensitive high articulationcontrol knob (222).

For finer adjustment of end effector (40) (see FIG. 11 ) relative totissue, the operator manipulates low articulation control knob (223). Inone example, the operator directs articulation section (130) (see FIG.11 ) slightly leftward to the desired position shown in FIG. 33 . Tothis end, the operator manipulates low articulation control knob (223)counterclockwise (when viewed from above) for leftward articulation ofarticulation section (130) (see FIG. 11 ). In turn, low articulationcontrol knob (223) directs low drive gear (296) similarlycounterclockwise. Low drive gear (296) engages low face gear (298) todirect drive drum (244) clockwise, which similarly directs articulationdrum (252) clockwise. As articulation drum (252) rotates clockwise,proximal and distal inner threads (262, 264) translate proximal anddistal lead screws (254, 256) longitudinally toward each other to thedesirable right configuration. Low articulation control knob (223) thusoperatively connects to drive drum (244) with low ratio drive (228) suchthat the predetermined amount of counterclockwise rotation of lowarticulation control knob (223) results in a relatively small degree ofarticulation of articulation section (130) (see FIG. 11 ). The operatormay thus more accurately and precisely selectively move end effector(40) (see FIG. 11 ) toward tissue with the more sensitive lowarticulation control knob (223).

While the above description of describes clockwise manipulation of higharticulation control knob (222) and counterclockwise manipulation of lowcontrol knob (223), counterclockwise and clockwise manipulation of highand low articulation control knobs (222, 223), respectively, will drivearticulation control assembly (218) opposite from that described above.Furthermore, the operator may desire to manipulate high and lowarticulation control knobs (222, 223) in any desirable order fortreating the patient. Alternatively, the operator may desire to only useone of the high and low articulation control knobs (222, 223). It shouldtherefore be understood that the use of surgical instrument (210) is notintended to be unnecessarily limited to the exemplary use describedherein. Furthermore, while the above described articulation controlassembly (218) is dual mode with two distinct sensitivities derived fromtwo high and low ratio drives (227, 228), it will be appreciated thatadditional modes and drives may be incorporated into articulationcontrol assembly (218) for additional sensitivities as found to bedesirable.

III. Exemplary Combinations

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. It should be understoodthat the following examples are not intended to restrict the coverage ofany claims that may be presented at any time in this application or insubsequent filings of this application. No disclaimer is intended. Thefollowing examples are being provided for nothing more than merelyillustrative purposes. It is contemplated that the various teachingsherein may be arranged and applied in numerous other ways. It is alsocontemplated that some variations may omit certain features referred toin the below examples. Therefore, none of the aspects or featuresreferred to below should be deemed critical unless otherwise explicitlyindicated as such at a later date by the inventors or by a successor ininterest to the inventors. If any claims are presented in thisapplication or in subsequent filings related to this application thatinclude additional features beyond those referred to below, thoseadditional features shall not be presumed to have been added for anyreason relating to patentability.

Example 1

A surgical instrument, comprising: (a) a shaft assembly defining alongitudinal axis, wherein the shaft assembly includes: (i) a proximalend portion, (ii) a distal end portion having an end effector, and (iii)an articulation section configured to deflect the end effector from thelongitudinal axis; and (b) an articulation control assembly connected tothe proximal end portion of the shaft assembly, wherein the articulationcontrol assembly includes: (i) a first articulation control member, (ii)a second articulation control member, and (iii) a transmission assemblycomprising: (A) a high ratio drive, wherein the high ratio drive isconfigured to drive the articulation section to deflect the end effectorat a high rate of articulation in response to actuation of the firstarticulation control member, and (B) a low ratio drive, wherein the lowratio drive is configured to drive the articulation section to deflectthe end effector at a low rate of articulation in response to actuationof the second articulation control member.

Example 2

The surgical instrument of Example 1, wherein the first articulationcontrol member is rotatably mounted relative to the shaft assembly andis configured to be rotatably manipulated, and wherein the secondarticulation control member is rotatably mounted relative to the shaftassembly and is configured to be rotatably manipulated.

Example 3

The surgical instrument of any one or more of Examples 1 through 2,wherein the transmission assembly further includes a drive memberoperatively connected to the articulation section and engaged with eachof the high and low ratio drives, wherein the drive member is configuredto be driven by each of the high and low ratio drives and transmitmovement from the high and low ratio drives toward the articulationsection for deflecting the distal end portion from the longitudinalaxis.

Example 4

The surgical instrument of Example 3, wherein the drive member comprisesa drive drum extending along the longitudinal axis, wherein the drivedrum is configured to be rotatably driven by each of the high and lowratio drives about the longitudinal axis.

Example 5

The surgical instrument of Example 4, wherein the low ratio driveincludes a first face gear and the high ratio drive includes a spurgear, wherein the first face gear is rigidly connected to the drive drumand extends about the longitudinal axis, wherein the spur gear isrigidly connected to the drive drum and extends about the longitudinalaxis, and wherein the first face and spur gears are configured tosimultaneously rotate about the longitudinal axis with the drive drum.

Example 6

The surgical instrument of Example 5, wherein the first face gear isconfigured to be rotatably driven via the second articulation controlmember, and wherein the spur gear is configured to be rotatably drivenvia the first articulation control member.

Example 7

The surgical instrument of Example 6, wherein the second articulationcontrol member comprises a low articulation control knob, and whereinthe first articulation control member comprises a high articulationcontrol knob.

Example 8

The surgical instrument of Example 7, wherein the low and higharticulation control knobs are respectively configured to rotate about alow transverse axis and a high transverse axis, and wherein each of thelow and high transverse axes are oriented perpendicular to thelongitudinal axis.

Example 9

The surgical instrument of Example 8, wherein the low ratio drivefurther includes a low bevel drive gear, wherein the low articulationcontrol knob is rigidly connected to the low bevel drive gear via a lowdrive shaft, wherein each of the low bevel drive gear and the low driveshaft are configured to rotate about the low transverse axis, whereinthe first face gear comprises a first bevel face gear, and wherein thefirst bevel face gear engages the low drive bevel gear to be rotatablydriven by the low drive bevel gear.

Example 10

The surgical instrument of any one or more of Examples 7 through 9,wherein the high ratio drive further includes a second face gear,wherein the second face gear rigidly extends from the high articulationcontrol knob, and wherein the second face gear is configured to rotateabout the high transverse axis.

Example 11

The surgical instrument of Example 10, wherein the high ratio drivefurther includes a drive coupling, wherein the drive coupling is engagedwith each of the second face gear and the spur gear and is configured tobe rotatably driven by the second face gear and thereby rotatably drivethe spur gear.

Example 12

The surgical instrument of any one or more of Examples 3 through 11,wherein the transmission assembly further includes: (A) an articulationdrum configured to rotate about the longitudinal axis, wherein thearticulation drum includes a plurality of inner threads about thelongitudinal axis, and (B) at least one lead screw engaged with theplurality of inner threads and configured to translate along thelongitudinal axis upon rotation of the articulation drum for flexing thearticulation section, wherein the high and low ratio drives areoperatively connected to the articulation drum such that selectivemanipulation of the high and second articulation control members isconfigured to rotate the articulation drum for flexing the articulationsection via the at least one lead screw.

Example 13

The surgical instrument of Example 12, wherein the at least one leadscrew is configured to self-lock without selective manipulation of thehigh and second articulation control members to thereby inhibit flexingof the articulation section and unlock with selective manipulation ofthe high and second articulation control members to thereby flex thearticulation section.

Example 14

The surgical instrument of any one or more of Examples 1 through 13,further comprising an end effector located at the distal end portion ofthe shaft assembly, wherein the end effector comprises an ultrasonicblade, wherein the shaft assembly further comprises an acousticwaveguide, wherein the acoustic waveguide is coupled with the ultrasonicblade, wherein the acoustic waveguide extends through the proximal endportion, the articulation section, and the distal end portion.

Example 15

The surgical instrument of any one or more of Examples 1 through 14,further comprising a disposable assembly and a handle assembly portion,wherein the disposable assembly includes the shaft assembly and thearticulation control assembly, and wherein the disposable assembly isconfigured to removably connect to the handle assembly portion.

Example 16

An articulation control assembly for a surgical instrument, comprising:(a) a body; (b) a shaft assembly extending distally from the body, theshaft assembly including an articulation section, wherein the shaftassembly defines a longitudinal axis; (c) an end effector located at adistal end of the shaft assembly, wherein the articulation section isoperable to selectively deflect the end effector away from thelongitudinal axis; (d) a first articulation control member; (e) a secondarticulation control member; and (f) a transmission assembly operativelyconnected to the body, the transmission assembly comprising: (i) a highratio drive, wherein the high ratio drive is configured to drive thearticulation section to deflect the end effector from the longitudinalaxis at a high rate of articulation in response to actuation of thefirst articulation control member, and (ii) a low ratio drive, whereinthe low ratio drive is configured to drive the articulation section todeflect the end effector from the longitudinal axis at a low rate ofarticulation in response to actuation of the second articulation controlmember.

Example 17

The articulation control assembly of Example 16, wherein thearticulation section is configured to flex to thereby deflect the endeffector away from the longitudinal axis.

Example 18

The articulation control assembly any one or more of Examples 16 through17, wherein the first articulation control member comprises a firstrotatable member, wherein the second articulation control membercomprises a second rotatable member, first and second rotatable membersare rotatable independently of each other.

Example 19

The articulation control assembly of Example 18, wherein the first andsecond rotatable members are rotatable about respective axes that areeach perpendicular to the longitudinal axis.

Example 20

A method of operating an instrument, wherein the instrument comprises:(a) a shaft assembly defining a longitudinal axis, wherein the shaftassembly has an articulation section; (b) an end effector secured to theshaft assembly; (c) a first articulation control, wherein the firstarticulation control is operable to actuate the articulation section tothereby deflect the end effector away from the longitudinal axis at afirst rate of articulation; and (d) a second articulation control,wherein the second articulation control is operable to actuate thearticulation section to thereby deflect the end effector away from thelongitudinal axis at a second rate of articulation; wherein the methodcomprises: (a) inserting the distal end of the shaft assembly into apatient while the articulation section is in a non-articulated state,such that the end effector is aligned with the longitudinal axis; (b)manipulating the first articulation control to provide coarse adjustmentof the articulation section, thereby deflecting the end effector awayfrom the longitudinal axis at a first rate of articulation; and (c)manipulating the second articulation control to provide fine adjustmentof the articulation section, thereby deflecting the end effector awayfrom the longitudinal axis at a second rate of articulation, wherein thesecond rate of articulation is lower than the first rate ofarticulation.

IV. Miscellaneous

It should be understood that any of the versions of instrumentsdescribed herein may include various other features in addition to or inlieu of those described above. By way of example only, any of theinstruments described herein may also include one or more of the variousfeatures disclosed in any of the various references that areincorporated by reference herein. It should also be understood that theteachings herein may be readily applied to any of the instrumentsdescribed in any of the other references cited herein, such that theteachings herein may be readily combined with the teachings of any ofthe references cited herein in numerous ways. Moreover, those ofordinary skill in the art will recognize that various teachings hereinmay be readily applied to electrosurgical instruments, staplinginstruments, and other kinds of surgical instruments. Other types ofinstruments into which the teachings herein may be incorporated will beapparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale,California. Similarly, those of ordinary skill in the art will recognizethat various teachings herein may be readily combined with variousteachings of U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Toolwith Ultrasound Cauterizing and Cutting Instrument,” published Aug. 31,2004, the disclosure of which is incorporated by reference herein.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometric s, materials, dimensions, ratios,steps, and the like discussed above are illustrative and are notrequired. Accordingly, the scope of the present invention should beconsidered in terms of the following claims and is understood not to belimited to the details of structure and operation shown and described inthe specification and drawings.

I/We claim:
 1. A surgical instrument, comprising: (a) a shaft assemblydefining a longitudinal axis, wherein the shaft assembly includes: (i) aproximal end portion, (ii) a distal end portion having an end effector,and (iii) an articulation section configured to deflect the end effectorfrom the longitudinal axis; and (b) an articulation control assemblyconnected to the proximal end portion of the shaft assembly, wherein thearticulation control assembly includes: (i) a first articulation controlmember, (ii) a second articulation control member, and (iii) atransmission assembly comprising: (A) a high ratio drive, wherein thehigh ratio drive is configured to drive the articulation section todeflect the end effector at a high rate of articulation in response toactuation of the first articulation control member, and (B) a low ratiodrive, wherein the low ratio drive is configured to drive thearticulation section to deflect the end effector at a low rate ofarticulation in response to actuation of the second articulation controlmember.
 2. The surgical instrument of claim 1, wherein the firstarticulation control member is rotatably mounted relative to the shaftassembly and is configured to be rotatably manipulated, and wherein thesecond articulation control member is rotatably mounted relative to theshaft assembly and is configured to be rotatably manipulated.
 3. Thesurgical instrument of claim 1, wherein the transmission assemblyfurther includes a drive member operatively connected to thearticulation section and engaged with each of the high and low ratiodrives, wherein the drive member is configured to be driven by each ofthe high and low ratio drives and transmit movement from the high andlow ratio drives toward the articulation section for deflecting thedistal end portion from the longitudinal axis.
 4. The surgicalinstrument of claim 3, wherein the drive member comprises a drive drumextending along the longitudinal axis, wherein the drive drum isconfigured to be rotatably driven by each of the high and low ratiodrives about the longitudinal axis.
 5. The surgical instrument of claim4, wherein the low ratio drive includes a first face gear and the highratio drive includes a spur gear, wherein the first face gear is rigidlyconnected to the drive drum and extends about the longitudinal axis,wherein the spur gear is rigidly connected to the drive drum and extendsabout the longitudinal axis, and wherein the first face and spur gearsare configured to simultaneously rotate about the longitudinal axis withthe drive drum.
 6. The surgical instrument of claim 5, wherein the firstface gear is configured to be rotatably driven via the secondarticulation control member, and wherein the spur gear is configured tobe rotatably driven via the first articulation control member.
 7. Thesurgical instrument of claim 6, wherein the second articulation controlmember comprises a low articulation control knob, and wherein the firstarticulation control member comprises a high articulation control knob.8. The surgical instrument of claim 7, wherein the low and higharticulation control knobs are respectively configured to rotate about alow transverse axis and a high transverse axis, and wherein each of thelow and high transverse axes are oriented perpendicular to thelongitudinal axis.
 9. The surgical instrument of claim 8, wherein thelow ratio drive further includes a low bevel drive gear, wherein the lowarticulation control knob is rigidly connected to the low bevel drivegear via a low drive shaft, wherein each of the low bevel drive gear andthe low drive shaft are configured to rotate about the low transverseaxis, wherein the first face gear comprises a first bevel face gear, andwherein the first bevel face gear engages the low drive bevel gear to berotatably driven by the low drive bevel gear.
 10. The surgicalinstrument of claim 7, wherein the high ratio drive further includes asecond face gear, wherein the second face gear rigidly extends from thehigh articulation control knob, and wherein the second face gear isconfigured to rotate about the high transverse axis.
 11. The surgicalinstrument of claim 10, wherein the high ratio drive further includes adrive coupling, wherein the drive coupling is engaged with each of thesecond face gear and the spur gear and is configured to be rotatablydriven by the second face gear and thereby rotatably drive the spurgear.
 12. The surgical instrument of claim 3, wherein the transmissionassembly further includes: (A) an articulation drum configured to rotateabout the longitudinal axis, wherein the articulation drum includes aplurality of inner threads about the longitudinal axis, and (B) at leastone lead screw engaged with the plurality of inner threads andconfigured to translate along the longitudinal axis upon rotation of thearticulation drum for flexing the articulation section, wherein the highand low ratio drives are operatively connected to the articulation drumsuch that selective manipulation of the high and second articulationcontrol members is configured to rotate the articulation drum forflexing the articulation section via the at least one lead screw. 13.The surgical instrument of claim 12, wherein the at least one lead screwis configured to self-lock without selective manipulation of the highand second articulation control members to thereby inhibit flexing ofthe articulation section and unlock with selective manipulation of thehigh and second articulation control members to thereby flex thearticulation section.
 14. The surgical instrument of claim 1, furthercomprising an end effector located at the distal end portion of theshaft assembly, wherein the end effector comprises an ultrasonic blade,wherein the shaft assembly further comprises an acoustic waveguide,wherein the acoustic waveguide is coupled with the ultrasonic blade,wherein the acoustic waveguide extends through the proximal end portion,the articulation section, and the distal end portion.
 15. The surgicalinstrument of claim 1, further comprising a disposable assembly and ahandle assembly portion, wherein the disposable assembly includes theshaft assembly and the articulation control assembly, and wherein thedisposable assembly is configured to removably connect to the handleassembly portion.
 16. An articulation control assembly for a surgicalinstrument, comprising: (a) a body; (b) a shaft assembly extendingdistally from the body, the shaft assembly including an articulationsection, wherein the shaft assembly defines a longitudinal axis; (c) anend effector located at a distal end of the shaft assembly, wherein thearticulation section is operable to selectively deflect the end effectoraway from the longitudinal axis; (d) a first articulation controlmember; (e) a second articulation control member; and (f) a transmissionassembly operatively connected to the body, the transmission assemblycomprising: (i) a high ratio drive, wherein the high ratio drive isconfigured to drive the articulation section to deflect the end effectorfrom the longitudinal axis at a high rate of articulation in response toactuation of the first articulation control member, and (ii) a low ratiodrive, wherein the low ratio drive is configured to drive thearticulation section to deflect the end effector from the longitudinalaxis at a low rate of articulation in response to actuation of thesecond articulation control member.
 17. The articulation controlassembly of claim 16, wherein the articulation section is configured toflex to thereby deflect the end effector away from the longitudinalaxis.
 18. The articulation control assembly of claim 16, wherein thefirst articulation control member comprises a first rotatable member,wherein the second articulation control member comprises a secondrotatable member, first and second rotatable members are rotatableindependently of each other.
 19. The articulation control assembly ofclaim 18, wherein the first and second rotatable members are rotatableabout respective axes that are each perpendicular to the longitudinalaxis.
 20. A method of operating an instrument, wherein the instrumentcomprises: (a) a shaft assembly defining a longitudinal axis, whereinthe shaft assembly has an articulation section; (b) an end effectorsecured to the shaft assembly; (c) a first articulation control, whereinthe first articulation control is operable to actuate the articulationsection to thereby deflect the end effector away from the longitudinalaxis at a first rate of articulation; and (d) a second articulationcontrol, wherein the second articulation control is operable to actuatethe articulation section to thereby deflect the end effector away fromthe longitudinal axis at a second rate of articulation; wherein themethod comprises: (a) inserting the distal end of the shaft assemblyinto a patient while the articulation section is in a non-articulatedstate, such that the end effector is aligned with the longitudinal axis;(b) manipulating the first articulation control to provide coarseadjustment of the articulation section, thereby deflecting the endeffector away from the longitudinal axis at a first rate ofarticulation; and (c) manipulating the second articulation control toprovide fine adjustment of the articulation section, thereby deflectingthe end effector away from the longitudinal axis at a second rate ofarticulation, wherein the second rate of articulation is lower than thefirst rate of articulation.